A CONTRACT METHOD in HIGH-SCHOOL CHEMISTRY M. P. SCHULTZ Senior High School, University City, Missouri
A method i s descri6ed whereby students of high-school the result of practical reseurch. It has been adupkd jrum chemistry are embled to advance indiwdually as fast as welbknoum methods, devehped through experience, and their capacity and application warrants. The method is based upon psychological principles.
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HE teaching of chemistry, or of other subjects, THE UNIVERSITY CITY METHOD for that matter, becomes a campaign against During the last four or five semesters this method "annoying states of affairs," the final goal being has taken rather definite form. It had its inception t o make each and every student feel that he is a success. more than a decade ago, when the Morrison plan was In order to succeed, one must achieve. For achievefound to be inapplicable in its entirety in the chemistry ment, effort is needed and for sustained effort, interest, department of the University City schools. initiative, and dependability are necessary. When the efforts are successful, interest is maintained, which HOW THE WORK IS PLANNED constitutes the chief motivation for further achieveThe assignments are written and preferably called ment. Whether or not the student succeeds depends not only upon his interest and capacity, but also upon contracts. Mimeographed copies of all are prepared the situation in which he finds himself, A favorable for the whole course before school opens. A contract situation demands definite assignments, explicit di- consists of twenty to forty questions and problems rection (at least in the beginning), adequate and based on the text and the laboratory manual. (See readily available supplies, equipment and references, example of contract below.) ..The text is the most demonstrations and explanations, time enough for available reference and is cited first. The other referpreparation, and, most important, time enough for ences are used if the student chooses. He may of the student to convince a qualified listener and observer cunrse employ any reference he finds useful, and the that the topic has been mastered. I t is in regard to advanced student often does so. A contract usually this last element in the situation, namely, time enough covers a chapter or two associated chapters. It is not for individual recitation, that tlie method about to be wise to make them longer for then it is more difficult described is believed to be unique. +The student has for the student to sustain his interest and effort. The for his auditor the teacher only and not the whole class contracts specify the minimum quantity of work to be (except occasionally, a small group, interested in the accomplished in order to conform to the demands of same topic), the reason being that the other members the State Course of Study, which is practically identical of the class either are not up to the topic in question, with the outline published by the American Chemical or have passed beyond it and hence are not much in- Society. An attempt has been made to provide for terested, but would rather utilize this time in pursu- additional work, which may for convenience be called ing their own work, instead of listening. Whatever the maximum. This sometimes deals with recent demeasure of success this method may have attained is velopments. A student may go beyond the minimum ascribed in part to recognition of the facts that most and maximum. The minimum designated by twelve selected conindividuals are able to converse intelligently upon topics with which they are familiar, and usually like to tracts, together with a satisfactory final examination, do so when the proper opportunity is presented. When meets the requirements for a passing semester grade. the opportunity is not given, disgust or even resent- It might be stated that the final examinations are of ment may develop. Most of us have heard the ex- the objective type, other than true-false, and are conpression, perhaps used it: "I knew my lesson, but was structed by the department. Several of them have renot called upon to recite." For these and other rea- liability coefficients, r12, of 0.90, or more, with probable sons it is of the utmost importance that a suitable com- errors of measurement, PE,, of less than 2. bination of conditions be made in order that the stuThere is no time limit set on a single contract, aldent may have his chance when he is ready. though a certain number are to be completed per semes-
ter. The average number of contracts completed per semester per person has been found to be approximately fifteen, corresponding to a grade of '"2," which of course may be altered somewhat, depending on the final examination, and other contributing factors. Grades are awarded every five weeks. They are based on the number of contracts completed, and, in some cases, upon the number of repetitions of tests, or recitations; since it would not seem fair to give the same grade to students who had completed an equal number of contracts, but one of whom it had been necessary to test repeatedly on the same contracts, thus showing he had exercised less judgment or dependability. These are special cases and relatively few. In general, for the five-week grade, " A may be given for five or more contracts, and "D" for two or three, depending on whether the maximum or its equivalent has been satisfactorily completed, and upon the length of the contracts. For the semester grade of "A," about twenty contracts should be mastered without repetition in conjunction with the examination. This is at the rate of approximately one contract per week of the school year. There are special contracts for students who complete the course early. Various topics such as milk, soil, inks, qualitative analysis, and titrations are treated. Some discrimination is exercised by the teacher toward the end of the semester in the selection of contracts for those who appear to have difficulty in completing the minimum. For example, it might be considered important that no one omit the contract on the periodic table, whereas the study of the heavy metals can be appreciably condensed. The laboratory where the work is carried on is well ventilated by forced draft through hoods built in each table. On centrally located open shelves the chemicals demanded by the laboratory manual are arranged in alphabetical and numerical order in bottles of uniform size. Each student is assigned a drawer with lock and a set of apparatus. Order is kept by means of a rotating monitor system. A combin&ion stock room and officeseparates the laboratory from the class room.
CONTKACT ON COldPLBTE AND
INCOMPLETE REACTIONS
Ref: Text A, pp. 292-301 Text B, pp. 363-374 Text C, pp. 1 5 s Text D, pp. 260Experiments Numbers 43, 44.45 in your manual. fully chanaes in directions.
Follow care-
What is the object of this chapter? By m y of review name four kinds of chemical changes. Illustrate each with one or more equations. Be able to read the equations and to state the conditions under which each reaction will occur. Why may these reactions he called irreversible? How are arrows used t o show that a chemical action is reversible? Give three examples of actions that are reversible. How may reversible actions be made t o go to completion? Example.
Name three ways in which reactions in general go to completion. Illustrate each with an equation, preferably selected from your laboratory work. What effect dws a decrease in one of the products of a reaction have on the reaction? How does an increase in the relative amount of a reagent influence the reaction? (This is called the "common-ion effect" in other texts.) What are the common ions in the example used by the author on page 296? What substances supply these ions? Select and state the sentences that explain why the ordinarily soluble salt, NaCI, becomes insoluble (is precipitated) under the conditions stated. See also your lecture notes. Why is it that an excess of barium chloride is used over the amount represented by the equation in the quantitative precipitation of barium sulfate? Explain why the addition of ammonium chloride to a solution of the base ammonium hydroxide makes the latter "weaker." How could a "weak" acid be made still "weaker"? I n general how does temperature affect the speedof chemical action? I n what process is it not desirable to increase the temperature beyond a certain point? Why? A high pressure is desirable, however. Why? What is the purpose of a catalyst in a chemical reaction? What is it that the catalyst does not alter? When will a catalyst become ineffective? Why is it important to us to have reactions go t o completion? Work exercises 1, 2,3, 5, 9, 12, pp. 300-1, in the text.
Additional Work Discuss "dynamic equilibrium." State the law of concentration and mention some of its applications. Work all exercises, pp. 300-1. What may he the practical use of a "heat of formation" table?
+ + + HOW THE WORK IS CARRIED ON
The usual recitation method is employed during the first three or four weeks 'of school. There is little difficulty in keeping the class together during this period. This time is essential for introducing the subject in order that the student may later be able t o set up apparatus and handle chemicals properly without constant supervision. As soon as the members of the class begin to draw apart, it is time for individual differences to be recognized. But it is only when he reports himself ready that the student is given a private hearing, which may be oral or written. For this hearing the teacher selects the questions, often a t random, from the contract. The student is considered to have mastered the contract when able to express himself intelligently and adequately concerning it. This is then indicated on the record with a check mark and the date. The student returns the completed contract to its file and obtains the next. He is now a free agent as far as deciding when he wishes to recite again is concerned. Thus a character element, responsibility, is introduced, which only the student himself can properly control. If complete mastery is not shown, the student is asked to return for reexamination. In such a case the record is marked with a small cross for each unsatisfactory recitation. The dates are also noted. This method of keeping score, together with the fact that when deficient he has to return among his fellows for further study with no alibi, or when successful he has that
feeling of a "satisfying state of affairs," has proved to be a powerful urge for the student to attempt mastery the k s t time. This induces assiduous application and requires the student to exercise his judgment in checking up on himself. It should be noted that the teacher evaluates the examination paper immediately in the presence of the student. It is thus possible to ask additional questions requiring oral replies. The questions may or may not be listed on the contract. If questions not listed call forth acceptable answers, the teacher will realize that he is dealing with an efficient student whose interest and comprehension go beyond the assignment. If the question is listed, the correct response will, of course, be expected from all. The advantages of the immediate evaluation of the test are apparent: the pupil learns without delay where he stands; the teacher is able to give hints then and there; no examination papers accumulate. The importance of these advantages cannot be overemphasized. The teacher's routine is as follows. After roll-call the students may ask questions. Demonstrations are given a t this time, or difficulties explained. After this period, each member of the class turns to his individual work. The teacher's attention is now available for those who have laboratory work to do. In five or ten minutes brief consultations are held, special apparatus is issued and similar items are disposed of. When the lahoratory work is under way, students are called for examination from the list on which they had indicated their readiness. To assign each his test by indicating the numbers of the questions to be discussed on paper takes only a few moments. If only two or three students are ready, oral tests are preferred. Written tests are given when the list is longer. There is practically no waiting list. Should a test be interrupted by the ending of the period, it is begun or completed the next day with different questions, but usually no one begins later than about ten minutes before the bell. This time is needed to complete the eyluation of the tests finished. The same questions are not given to students writing simultaneously on the same contract. In the intervals between tests the teacher visits the laboratory, or helps the students in the classroom, or both. A prerequisite for admission to the examination is that the laboratory manual be in good order. It is inspected before the test, and any errors or omissions are to he rectified before the student is allowed to continue. Should anyone copy an approved manual, it will profit him very little unless he actually learns thereby, for there are no separate laboratory and class grades. The test covers both.
mastery of such a series of contracts, with the implication that mere memory work has little educational value. The fact is admitted, hut the implication is denied. Learning begins in the accumulation of facts. Whether learning continues through association and generalization will depend upon the biological heredity and the interest of the student himself after his environment has been made as favorable as possible. Moreover, there really is no such thing as mere memory work even in the memorization of nonsense. "So in memorizing as in learning a maze, all of one's mental processes and other types of reactions may be employed."* Apropos of another inquiry, it might be said that there are practically no problems of discipline. Such problems are perhaps minimized by the fact that the course is elective, and, since chemistry is usually considered a difficult subject, the students who elect it are apt to be more competent than would otherwise be the case. This assumption may be supported by the final results. Out of 113 students enrolled, 102 passed, 3 withdrew during the semester to change residence,aud 8 withdrew for other reasons from time to time during, the semester. The final record therefore listed no failures. This result, however, it is believed, is attributable in part to the method. It might he suggested that the, demonstrations lose some value because they are presented to s t u d h t s a t different stages in their progress under the contract method. But it should be realized that under 'the ordinary recitation method, the students are also in different stages of progress. Under either method the teacher's judgment will determine the most appropriate time for the demonstration.
co~c~usro$ Favorable comments have been made onthe method and its results. I t is now being tried in the biology department under competent direction. The chemistry classes prefer it. This has been determined by ballot. Due credit should therefore be accorded the students. One might speculate on the reasons for their prefererlce. It certainly is not because there is less to be done. Can it be because the students like to practice self-determination in their endeavors? Can it he because they like to accept responsibility for their own progress and receive the reward in the form of "a satisfying state of affairs" when the responsibility is being suitably discharged? Do they find the opportunity attractive to converse or recite more fully on topics they have mastered? Do they find learning satisfying for its own sake and therefore work for something more than a grade? Is it possible that some of them understand that elementary chemistry, besides being a field rich in information, may also he an instrument for the development of desirable habits of thought and action, which ADDITIONAL OBSERVATIONS in turn may become vehicles useful in further acquisiIt may he of value to discuss briefly certain questions tion of knowledge and the building of character? One that have been asked concerning the above-described would -like to believe so. method. One of these inquiries is concerned with the * GATES,ART^ I., "Psychology for students of education," considerable amount of memory work involved in the The Macmillan Company. New York City. 1927, p. 247.
